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The .45 Colt

By Chuck Hawks

.45 Colt
Illustration courtesy of Hornady Mfg. Co.

The .45 Colt, sometimes called the .45 Long Colt to distinguish it from the short .45 cartridge historically required by the S&W Schofield revolver, as well as the .45 ACP (also sometimes, incorrectly, referred to as the .45 Colt), is the oldest service cartridge still in use today. It was introduced in 1873 for the then new Colt Single Action Army (SAA) revolver, the famous Peacemaker. The .45 Colt and the SAA revolver quickly became legends in their own time, and the most popular handgun/cartridge combination on the Western frontier.

The most common factory loads for the .45 Colt give a 225 grain lead HP bullet a muzzle velocity of 960 fps and an energy of 460 ft. lbs. Or a 250-255 grain lead bullet a MV of 860 fps and a ME of 410 ft. lbs. The mid-range trajectory of this load shows a rise of 3.2" over 75 yards.

Physically, the .45 Colt is a typical, straight wall, rimmed revolver cartridge. Its rim diameter is .512", its base diameter is .480", and its neck diameter is .476". The case length is 1.29" and the overall cartridge length is 1.6". The .45 Colt uses .454" diameter bullets and standard large pistol primers. The SAAMI maximum average pressure is pegged at 14,000 psi.

I have owned a .45 Colt revolver for many years now, and I have a reasonable amount of experience reloading for the cartridge. For recreational shooting I load the 200 grain Speer "flying ashtray" JHP bullet in front of 11.0 grains of HS6 powder for a muzzle velocity (MV) of 945 fps. This is a normal pressure load. In fact, HS6 can launch the 200 grain bullet at up to 1081 fps in front of 12.5 grains of HS6 powder, according to the Speer Reloading Manual #13.

I assure you that , based on my testing, you would not want to see someone hit by one of those bullets. That bullet expands violently at .45 Colt velocities.

For those who prefer a 250 grain lead bullet, the same Speer reloading manual suggests 11.0 grains of HS6 powder for a MV of 917 fps, or 12.0 grains of HS6 for a MV of 945 fps.

The Speer 260 grain JHP bullet can be driven to a MV of 810 fps by 10.5 grains of HS6, and a maximum charge of 11.5 grains of HS6 yields a MV of 925 fps. Note that these are not "+P" loads.

High pressure loads, up to 25,000 cup, intended for use in Ruger Blackhawk and T/C Contender pistols only are also listed in the Speer manual. The top such loads listed use W296 and H110 powders. For example, 20.7 grains of W296 powder behind the 300 grain Speer bullet achieved a MV of 1084 fps, and 23.0 grains of W296 drove the 300 grain bullet to a MV of 1193 fps. Needless to say, the recoil and report of such loads is ferocious!

All of these Speer loads used Winchester cases and CCI primers. Particularly for the reloader, there is nothing that the .45 ACP cartridge can do that the old .45 (Long) Colt cannot do better.

Note: A full length article about the .45 Colt can be found on the Handgun Cartridge Page.

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Copyright 2004, 2015 by Chuck Hawks. All rights reserved.